In accordance a recent rapid industrialization and aging phenomenon of modern society, brain-related diseases have become a major issue in addition with an increase in various other diseases. A representative cause of the brain-related diseases may be excessive stress. The excessive stress is inevitable in accordance with rapid industrialization and development of the modern society, which induces progression of brain dysfunction such as insomnia, depression, attention disorder, memory loss, oxidative damage, and aging, such that Alzheimer syndrome, Parkinson syndrome, Huntington syndrome, and functional disorders of a brain tissue have prevalently and gradually increased, and accordingly, social costs also have steadily increased.
In general, the damage to the brain tissue due to excessive stress primarily causes a torpor state as physical response and kills cells configuring various parts of the brain, particularly hippocampus to block neurotransmission paths toward cerebrum, thereby inducing various brain dysfunctions (behavioral disorder and memory loss), and promotes secretion of stress hormone due to excessive activation of an HPA axis (hypothalamic-pituitary-adrenal axis) caused by stress reaction. The secretion of the stress hormone secondarily results in excessive occurrence of reactive oxygen species (ROS) and a lack of an antioxidant system (glutathione system, superoxide dismutase, and catalase) which is a defense mechanism removing the reactive oxygen species and even results in constraining physical activity due to a complex dysfunction of the brain tissue.
Clinically, the most important step affecting condition of a patient at various stages of oxidative brain damage and brain dysfunction induced by excessive stress and a progression of the diseases is to inhibit damage to hippocampus, or is to inhibit progression of liver cirrhosis if the damage to hippocampus already starts. Therefore, most of a number of researchers studying treatment of oxidative brain damage and brain dysfunction have made an effort to prevent such diseases and to develop therapeutic agents. Nevertheless, there are still no special treatment or medications.
Due to an effort to develop various drugs (Acetyl-L-Carnitine-HCl and MAO, PNMT and COMP inhibitor) globally and secure scientific basis thereof so as to solve the above-described problems, a partial efficacy in improving metabolism and inflammation of stress hormone has progressed, however, fundamental solutions in view of stability and accurate action mechanism of the drugs still remain.
As a result of studying and experimenting with various combinations of medicinal herb compositions in animal models suffering from damage to brain tissue and brain dysfunction induced by oxidative brain tissue damage, the present inventors found that an extract of Astragali Radix and Salvia Miltiorrhizae Radix was effective in preventing and treating damage to the brain tissue and the brain dysfunction, and completed the present invention.